Parecoxib API is a selective cyclooxygenase-2 (COX-2) inhibitor prodrug used for the short-term management of acute postoperative pain. In pharmaceutical products, Parecoxib is administered in its water-soluble sodium salt form, Parecoxib Sodium. EMA identifies parecoxib sodium as the active substance in Dynastat, with the therapeutic indication of short-term treatment of postoperative pain in adults.
Parecoxib Sodium has the molecular formula C19H17N2NaO4S, molecular weight 392.40 g/mol, and CAS Number 198470-85-8. The free Parecoxib compound is chemically distinct, with CAS 198470-84-7, molecular formula C19H18N2O4S, and molecular weight 370.40 g/mol. For pharmaceutical API pages relating to the injectable drug substance, Parecoxib Sodium should therefore be used as the primary API identity.
PubChem confirms Parecoxib Sodium as a water-soluble injectable sodium salt of Parecoxib, with molecular weight 392.4 g/mol and CAS 198470-85-8.
Parecoxib Sodium is used as an injectable prodrug of valdecoxib, which is the active COX-2-selective compound formed following enzymatic hydrolysis of parecoxib. EMA identifies parecoxib as a COX-2 selective NSAID used for the short-term treatment of postoperative pain in adults.
Applications include:
Parecoxib is a prodrug of valdecoxib. Following administration, parecoxib is hydrolyzed by carboxylesterases to valdecoxib, which selectively inhibits COX-2. This mechanism reduces prostaglandin production associated with pain and inflammation.
The sodium salt improves the aqueous solubility characteristics required for an injectable pharmaceutical product. Parecoxib Sodium is described as very soluble in water, making it suitable for preparation of injectable formulations.
Parecoxib Sodium is described as a white to off-white solid and is very soluble in water. Its molecular formula is C19H17N2NaO4S and its molecular weight is approximately 392.40–392.41 g/mol.
A pharmaceutical reference standard source reports Parecoxib Sodium as a powder and provides a water solubility of approximately 2 mg/mL under its specified analytical conditions. Other pharmaceutical information describes the material as very soluble in water, demonstrating that solubility values can depend on measurement conditions and material form.
Quality control of Parecoxib Sodium API should include appropriate identity, assay, impurity, inorganic impurity, residual-solvent and physical-property testing.
Analytical testing can include:
A published Parecoxib Sodium API specification reports pH 7.5–8.5, chloride NMT 0.02%, sulfate NMT 0.02%, and sodium propionate NMT 0.5%. These values should be regarded as a referenced API specification rather than presented as a universal current pharmacopoeial release specification.
Elemental impurity assessment is relevant to Parecoxib Sodium API because manufacturing processes can introduce trace inorganic contaminants. A published ICP-MS study specifically evaluated Cd, Pb, As, Hg, Co, V, Ni, Li, Sb and Cu in Parecoxib Sodium in the context of ICH Q3D risk assessment. The reported concentration limits were 0.2, 0.5, 1.5, 0.3, 0.5, 1, 2, 25, 9 and 30 ppm, respectively, in the study's evaluated specification framework.
These values should not automatically be entered as universal API release limits because elemental impurity acceptance criteria are dependent on the intended route of administration, daily exposure and applicable ICH Q3D assessment.
Residual solvents should be controlled according to the applicable pharmaceutical specification and ICH Q3C requirements. A published Parecoxib Sodium API specification lists limits for solvents including ethylbenzene, ethyl acetate, triethylamine, dichloromethane, n-hexane, ethanol, tert-butyl methyl ether, tetrahydrofuran and benzene.
For a general CMS product page, it is preferable not to present those process-specific solvent limits as universal pharmacopoeial requirements unless the exact manufacturing specification is being represented.
Parecoxib Sodium Bulk API is relevant to manufacturers developing or producing injectable pharmaceutical products. Because the pharmaceutical active ingredient is supplied as the sodium salt, procurement and regulatory documentation should clearly identify the material as Parecoxib Sodium, CAS 198470-85-8, rather than using the free Parecoxib CAS number.
The distinction is important:
PubChem independently confirms both chemical identities and their different molecular formulas and CAS numbers.
For the marketed injectable product Dynastat, EMA states that no special storage condition is required before reconstitution, while the Australian product information for Parecoxib Sandoz specifies storage below 30°C and protection from light. These are finished-product conditions and should not automatically be treated as bulk API storage specifications.
| Parameter | Specification |
|---|---|
| Appearance | white to off-white crystalline powder |
| Identification | IR & HPLC compliant |
| Assay (HPLC) | 98.0% – 102.0% |
| Loss on Drying | NMT 5.0% |
| Residue on Ignition | NMT 0.1% |
| pH (1% Solution) | 7.5–8.5 |
| Individual Impurity | NMT 0.5% |